Recent content by leedrong

Dear all ~! We designed M90 stud bolt and heavy nus for tightening two flanges with bolt tensioner . End user request to add Belleville spring washers . But if we use Belleville washers , Tentioner side washer absorb some of tension when tentioner released because this side nut turned by hand...

Our final decision is 1) change the type of tube material from TP430 to 304L 2). change the welding of tube to tube sheet from strength weld only to heavy expanding plus seal welding . Many thanks for your good advice.

Thanks ~! Mr.metengr The crack exist in circle along with welment mostly . But some of them are cross crack . Do you think the selection of welding rod Inconel 82 was bad choice than ER309 ? We will change tube material to ss304L from ss430 When we fail stop the crack. Mr.rmw We did...

Thanks ~! Tube to Tubesheet joint is strenth weld with RT except expand roll .It was a licenser's standard. PWHT was not recomende by licenser. The weld joint figure is tubesheet side J-groove 3mm depth 2.2mm width ,tube end is 1mm below than tubesheet surface, the total weldment thickness...

Dear All We have very urgent and critical problems on operation starting stage of boiler feed water heater. The heater was erected after hydrostatic pressure test at fabricator's shop without any problems. * Shell --- SA516-60 ,ID1130 * 44t * Tubes ---SA268-TP430 , OD25.4*2.108t*3250L...

Dear Mr. In ASME ,Mandatory Apendix 5 ,"Flanged and Flued or Flanged only Expansion Joints" clause 5-4(f) says that Nozzles,backing strips,clips,or other attachments shall not be located in highly stressed areas of the expasion joint , i.e., inner torus, annular plate and outer torus. We...

Hi Anybody knows proper plate mill maker who could supply plate as following specification . "" Carbon and low alloy steels shall be limited to a maximum yield strenth (Re) of 355 Mpa and maximum ultimate tensile strength (Rm) of 620 Mpa "" Plate supplier could guarantee 430 Mpa ,Maximum...

Dear Sir ~! Should a nozzle be made a forged body when design base on below specification of pressure vessel? *** Integrally reinforced nozzle shell be used in vessels with a shell thickness above 50mm *** We proposed 3 pieces of forged material to be welded join , a forged weld neck...

Hi~! Gentleman . Design condition of equipment is as followings. * Dt( centigrade ) : 560 /530 ( Shell side /Tube Side ) * O.t( Centigrade ) : 450 /420 * DP (kg/cm2G ) : 7 /10 * OP (kg/cm2G ) : 4 / 8 Material is all sus 321 We failed to pursuade client not...

Many Thanks Mr.Metengr We already proposed not perform PWHT to client but rejected. Specification crealy says that all welds of equipment shall be post weld heat treated and blocked and suppoted as necessary to avoid any deformation or damage.

Dear All We are just about to perform PWHT of Heat Exchanger Shell have 20 mm thickness ,2000 mm Dia ,6000mm in length,SA240-321 Material. PWHT temprature and hodilg time is 900 degree centigrade for 4 ours minmum. We have no experience PWHT like this high temperature for long time for the...

Any Idea? When move QC office to another building , All RT film was lost for a item completlty .The report was found and AI have the check sheet his own for the item. But clint inspector not yet reviewed it. He is requesting to reshoot all lost film arguing RT film must keep until final review...

We did PWHT after Inconel buttering on 9cr and weld using 309L with 410. But the result was crack along weld boundary Inconel butter weld with 309L at 120 angle during bend test. Do We need to use Inconel welding rod instead of 309L? Is it final applicable choice ?

Many Thanks ~! The failed section and area was bonded area of 410ss side on bend and tensile test. Still I want try welding with 309L welding rod without buttering. when I fail again ,second try will be Buttering both side with 309L and PWHT and welding with 309L. How about my plan .

Hi ~!Specialist Anyone who know the suitable welding rod material for welding 9cr to A410 stainless steel ? We failed qualification test using 309 welding rod . The cost is too fuge when we use Inconel welding rod (ER NiCr-3 )because calculated required welding rod is 3000 kgs...